41 lines
1.3 KiB
Python
41 lines
1.3 KiB
Python
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import os, sys
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import sqlite3
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from pkg_resources import resource_string
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class DBError(Exception):
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pass
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def get_schema(version):
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return resource_string("wormhole", "db-schemas/v%d.sql" % version)
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def get_db(dbfile, stderr=sys.stderr):
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"""Open or create the given db file. The parent directory must exist.
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Returns the db connection object, or raises DBError.
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"""
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must_create = not os.path.exists(dbfile)
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try:
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db = sqlite3.connect(dbfile)
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except (EnvironmentError, sqlite3.OperationalError), e:
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raise DBError("Unable to create/open db file %s: %s" % (dbfile, e))
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db.row_factory = sqlite3.Row
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VERSION = 1
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if must_create:
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schema = get_schema(VERSION)
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db.executescript(schema)
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db.execute("INSERT INTO version (version) VALUES (?)", (VERSION,))
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db.commit()
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try:
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version = db.execute("SELECT version FROM version").fetchone()[0]
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except sqlite3.DatabaseError, e:
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# this indicates that the file is not a compatible database format.
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# Perhaps it was created with an old version, or it might be junk.
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raise DBError("db file is unusable: %s" % e)
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if version != VERSION:
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raise DBError("Unable to handle db version %s" % version)
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return db
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